Brimstone Energy was founded with the goal of decarbonizing cement production. The founders adopted a “learn first” philosophy: develop the technology, build a pilot plant, gather cost and performance data, then choose a commercialization strategy. Patient investors and the U.S. Department of Energy (DOE) had provided $270 million to fund this approach, when, in June 2025, the DOE terminated its grant, which amounted to almost two-thirds of the company’s .....more